Shannon-St. Mary's will now represent Munster in the All Ireland Series next month after this hard fought victory.
This game was in the balance right up to the end when the Limerick Parish side settled the contest with a try from out half Conor Burns following a ruck close to the Bandon line.
Bandon did rally with time running out but the nearest they came to a score was drop goal effort by out half Jack Murphy which fell short of the posts.
Shannon-St. Mary's had the advantage of the strong wind in the opening half and Simon Gallagher looked like he was in for a try for the Limerick side but was held up on the line.
Burns was off target with a long range penalty attempt for Shannon-St. Mary's but made amends on twenty seven minutes when he opened the scoring with a penalty from the Twenty Two.
Bandon struck back and were level on the stroke of half time when scrum half Richard Walsh kicked a penalty.
Walsh put Bandon ahead with a second penalty effort twelve minutes into the second half, a lead they held until Shannon's late revival.
Scorers Bandon: Richard Walsh 2 penalties.
Shannon-St. Mary's: Conor Burns 1 try & 1 penalty.
Bandon: Gearoid Crowley; Christian Mulcahy, Jack Robinson, Olan Crowley, Gearoid O'Leary; Jack Murphy, Richard Walsh; Colin Jackson, Kevin Hurley, Ross Bateman; Fionn O'Murchu, Nicky Walsh; Tadhg O'Donovan, Darragh Coffey, Michel Beecher.
Replacements: Andrew Fitzgibbon, James Hill, Darren Curtin, Enda Phelan, Eoin Kelly, Brian Crowley, Mighty Okafor.
Shannon-St. Mary's: Ronan Hunt; Shane Ryan, Tim Tobin, Mel Corbett, Niall Fitzgerald; Conor Burns, David Evans; Gearoid Heelan, Graham Britchfield, David Wallace; Piaras O'Flynn, Craig McCallum; Ryan Meaney, Eoin McCabe, Cronan Gleeson.
Replacements: Damien Joy, Danny O'Shaughnessy, Simon Gallagher, Devlin Price, Conor Rafferty, Ben Coady, Scott Cusack.
Referee: Robert Coughlin (M.A.R.)